Pregnant Sows Research Articles

Specific features of the microbial resistance assessment in pig breeding enterprises

Abstract. The aim of this work was to study the opportunistic microbiocenosis of a pig-breeding enterprise and analyze its resistance to antimicrobial drugs (AMR- status). Methods. For two years on the pig farm there were taken samples of microflora from the mucous membranes and teats of pregnant and farrowed sows, from the mucous membranes and skin of piglets of weaning, rearing, fattening groups; from equipment, fencing, surfaces and inventory in different technological areas. The microorganism isolates isolated from the samples were determined for their sensitivity to antibiotics, which are most often used in veterinary practice and feeding in this region. Results. It was established that the surveyed enterprise has an unfavorable AMR-status. The nucleus of the opportunistic microbiocenosis was represented by S. aureus, Ent. faecium and P. aeruginosa, which accounted for about 44 % of the isolated isolates, while the isolates of these microorganisms in 85 % of cases had reduced sensitivity or resistance to one or more antibiotics. Multidrug resistance was found mainly in S. aureus isolates, which in 16 % of cases were resistant to three antibiotics, and in 7 % of cases – to six studied antibiotics of various classes. Most often, multidrug-resistant staphylococcus aureus was detected in sows and piglets in the weaning phase. Also, during the research, there was found a high resistance of opportunistic microflora isolates to tetracycline, which had been used in this farm for more than three years. More than 10 % of tetracycline-resistant S. aureus and Ent. isolates were found on the skin and mucous membranes of fattening pigs. faecium, which indicated an increased risk of contamination of raw meat at the slaughter stage by microorganisms carrying genes for resistance to tetracyclines. The novelty of this work lies in obtaining relevant data on the AMR status of a pig-breeding facility and identifying the most unfavorable technological areas in terms of microbial resistance. The research is executed at the expense of a grant of the RSF (project No.18-16-00040).

Influence of stress factors on adaptive and behavioral responses in sows and piglets

The article presents data from the scientific literature describing the influence of stress factors on pigs in modern production conditions. It was established that stress factors that affect sows during gestation period affect fetal development and are important determinants of behavioral disorders in piglets in the future. Conditions for keeping and feeding pregnant sows play an important role in ensuring the behavior of future offspring. Stress of sows in the late stages of gestation can cause a negative longterm effect on the functioning of the immune system of piglets. This reduces the ability of piglets to be effectively protected against infections during lactation and weaning periods. Changes in the endocrine and neurotransmitter systems depend on the gestational period, with late pregnancy being the most sensitive phase in pigs. Ensuring optimal housing conditions for sows and newborn piglets is an important condition for the proper development of protective, feeding and behavioral reflexes and, accordingly, the realization of their productive qualities. Stress factors also affect pigs in the postnatal period of their development. The main stress-inducing factors are the conditions of feeding, maintenance and technological methods associated with ensuring veterinary wellbeing. Early social isolation during the early postnatal life of animals causes persistent changes in their behavioral responses and physiological mechanisms of adaptation. Raising pigs in a depleted environment may indicate the presence of chronic stress and, accordingly, a decrease in the level of welfare, protective and productive qualities in animals. The methods that can reduce stress and improve animal welfare is environmental enrichment and adaptation of the housing environment according to the behavioral needs of animals. Ecological enrichment can be used to preserve or restore physiological homeostasis and behavioral disorders in the post-stress period. Key words: stress, pigs, adaptation, behavior, immune system, productivity.

Comparative Analysis Using Pulsed-Field Gel Electrophoresis Highlights a Potential Transmission of Salmonella Between Asymptomatic Buffaloes and Pigs in a Single Farm.

Buffaloes and pigs play an important epidemiological roll in the Salmonella infection cycle, and asymptomatic animals can act as key component in the dissemination of the disease by horizontal, vertical, and cross-species transmission. Our study aimed and was able to confirm evidences of a cross-species transmission of Salmonella Agona between asymptomatic buffaloes and pigs. Also, we described Salmonella infection within the pig production phases, involving serotypes Agona, Senftenberg and Schwarzengrund. Rectal samples were collected from Jafarabadi buffaloes (n = 25) and Piau pigs (n = 32), located on a single farm. Salmonella Agona was isolated from lactating buffaloes, gilts, pregnant sows, and weaned pigs, Salmonella Schwarzengrund from lactating sows and Salmonella Senftenberg from gilts, pregnant sows, lactating sows, and weaned pigs. Pulsed-field Gel Electrophoresis protocol (PFGE) was performed and revealed four different profiles. Profile 1 (Salmonella Agona), isolated from a pregnant sow, a gilt and two lactating buffaloes, revealed a indistinguishable PFGE pattern, confirming evidences of potential cross-species transmission. Profile 2 (Salmonella Agona), 3 (Salmonella Senftenberg), and 4 (Salmonella Schwarzengrund), isolated from pigs, revealed important indistinguishable PFGE patterns, evidencing Salmonella infection within the pig production phases. Considering the epidemiological relevance of buffaloes and pigs in the cycle of Salmonella infection, confirmation of a potential cross-species transmission of Salmonella Agona and potential Salmonella infection within the pig production phases highlights the importance of the correct establishment of preventive health strategies in farms, in special the importance of avoiding contact between buffaloes and pigs, since cross-species transmission can occur, increasing the risk of spreading the disease.

The Effect of Bacillus licheniformis-Fermented Products and Postpartum Dysgalactia Syndrome on Litter Performance Traits, Milk Composition, and Fecal Microbiota in Sows.

Simple SummarySupplementation of probiotics can shape the gut microbiota of sows and further influence their offspring’s gut microbiota. Postpartum dysgalactia syndrome (PDS) is a common disease in sows worldwide. Sows with PDS have depressed milk production and increased piglet mortality. The bacterial pathogen is an important factor in the etiology of PDS. Bacillus licheniformis-fermented products (BLFP) containing probiotics and antimicrobial substances can prevent disease and improve growth performance in broilers and weaning piglets. However, little is known about the effect of BLFP, PDS, and interaction on litter performance traits, milk composition, and fecal microbiota in sows. In this study, the effects of BLFP and PDS on sows were evaluated. Results show that BLFP supplementation in the diet of sows improves the piglet body weight at weaning. Dietary supplementation of BLFP or PDS differentially regulates the fecal microbiota of sows.This study was designed to evaluate the effects of Bacillus licheniformis-fermented products (BLFP) and postpartum dysgalactia syndrome (PDS) on litter performance traits, milk composition, and fecal microbiota in sows in a commercial farrow to finish pig farm. Fifty multiparous cross-bred pregnant sows were randomly assigned to two groups in a completely randomized design. The dietary treatments comprised a basal diet (pregnancy and nursery diet) as control and basal diet supplemented with 1.5 g/kg of BLFP. Sows with PDS in the two groups were further verified 12 h post-partum. Results show that the piglet body weight at weaning was increased in sows fed the BLFP compared to those fed the control diet. The milk fat content of prepartum sows was reduced in sows fed the BLFP. Postpartum sows with PDS had increased milk solid content compared with healthy sows. Microbial composition and species relative abundance analysis indicated distinct bacterial clusters between the groups. The abundance of the family Prevotellaceae in the feces decreased in sows with PDS. BLFP increased the average abundance of the genus (Eubacterium) coprostanoligenes group in feces of sows. These findings demonstrate that BLFP in the diet of sows can improve the piglet body weight at weaning and modulate the fecal microbiota of sows. PDS also has an impact on milk composition and fecal microbiota in sows.

Reproductive traits and blood biochemical parameters of sows when using a vitamin feed additive “LipoCar”

The reproductive traits of sows are of paramount importance in the production of high-quality pork. The world experience of pig farming shows the need to solve first of all the feed problem. Diets unbalanced in the content of vitamins restrain the manifestation of genetically inherent high prolificacy of sows. The purpose of the research was to study the influence of feeding the vitamin feed additive “LipoCar” on the reproductive traits of sows and the biochemical parameters of blood serum. The results of research on the introduction of vitamin feed additive “LipoCar” into the diet of pregnant sows have been presented in the article. The experiment has been carried out in the production conditions in JSC “Linevsky pedigree farm” on sows of Large White breed. Pregnant sows have received a basic diet, balanced for all the normalized elements of nutrition. Sows of the experimental group in the composition of the basic diet fed the feed additive “LipoCar”. The dosage of the drug “Lipocar” was 2,1 g/head/day. “Lipocar” has been fed for 20 days. The total duration of the experiment was 3 months. When introducing the vitamin feed additive “LipoCar” into the main diet of sows in the second half of pregnancy the increase in the number of piglets in the litter by 1,6-6,8 % and the weight of the litter – by 5,6-56,2 % (P ≤ 0,001) have been revealed in comparison with the control group of animals. There was a higher content of carotene in the blood serum of sows of the experimental group by 50,0 % (P ≤ 0,01), vitamin A - by 48,7 % (P ≤ 0,05), and total protein – by 4,9 % (P ≤ 0,05).

Herd-level factors associated with non-productive days and farrowing rate in commercial pig farms in two consecutive years

Non-productive days (NPD) and farrowing rate (FR) are indicators related to the number of piglets weaned per sow per year. Identifying the factors that affect these two indicators can improve the productivity and profitability of pig production. The objective of this study was to identify and quantify the associations of some factors related to the performance, management, facilities, feeding, health, and biosafety on NPD and FR over two consecutive years, using an inquiry applied to commercial pig farms in Brazil. Data from 150 farms were collected for a total study population of 135 168 sows, including gilt replacement, breeding (mating), gestation and farrowing/lactation phases. A questionnaire focusing on reproductive performance (for the years 2014 and 2015), management, facilities, feeding, health, and biosafety was administered. Multiple regression models were used to assess associations (α = 0.05) between factors and NPD and FR. An increased abortion index was associated with higher NPD (2014) and reduced FR (2014 and 2015); an increase in stillbirths was associated with higher NPD (2014 and 2015), and increased sow mortality was associated with a reduction in FR (2014 and 2015). In addition, farms had lower NPD in 2014, as the sows were younger at first farrowing, and when they had no lined ceiling in the gestation barns. Farms had lower NPD in 2015 when gilts were mated with an average weight of ≤139 kg compared to farms that mated gilts with an average weight >139 kg. Farrowing rate in 2014 was better in farms that fed pregnant sows with liquid/soup diets rather than mash or pelleted diets. Farms with higher FR in 2015 had wet-dry feeders in the farrowing barns rather than separate feeders and drinkers; they also practiced all-in/all-out management in farrowing rooms rather than continuous management. Several factors affect NPD and FR, but in general these factors do not remain the same over the years. Particular attention should be given to reducing abortions, stillborn piglets and the mortality of sows.

Alterations in the Blood Parameters and Fecal Microbiota and Metabolites during Pregnant and Lactating Stages in Bama Mini Pigs as a Model.

This study was conducted to analyze plasma reproductive hormone and biochemical parameter changes, as well as fecal microbiota composition and metabolites in sows, at different pregnancy and lactation stages, using Bama mini pig as an experimental animal model. We found that plasma prolactin (PRL), progesterone, follicle-stimulating hormone (FSH), and estrogen levels decreased from day 45 to day 105 of pregnancy. Plasma total protein and albumin levels were lower in pregnant sows, while glucose, urea nitrogen, total cholesterol, and high-density lipoprotein-cholesterol, as well as fecal acetate, butyrate, valerate, total short-chain fatty acids, skatole, and tyramine levels, were higher in lactating sows. Interestingly, the lactating sows showed lower α-diversity and Spirochaetes and Verrucomicrobia relative abundances, while pregnant sows showed a higher Proteobacteria relative abundance. Notably, the Akkermansia relative abundance was highest on day 7 of lactation. Spearman analysis showed a positive correlation between plasma triglyceride and cholinesterase levels and Akkermansia and Streptococcus relative abundances. Moreover, Oscillospira and Desulfovibrio relative abundances were also positively correlated with plasma FSH, LH, and E2 levels, as well as PRL and LH with Bacteroides. Collectively, plasma reproductive hormones, biochemical parameters, and fecal microbiota composition and metabolite levels could alter along with pregnancy and lactation, which might contribute to the growth and development demands of fetuses and newborns.

Biogas potential of swine manure of different animal classes

ABSTRACT In regions with developed animal husbandry, there is a problem of utilization of animal waste, which could be used as raw material for biogas production. In Russia most of the stations are designed and built by foreign companies taking into account generalized data on the properties of substrate. The particular characteristics of the local raw materials and substrates are not considered in the design process. Subsequently, this factor negatively affects the efficiency of biogas plants. In order to solve the problem, it is necessary to study the biogas potential of local substrates. The novelty of this work is to identify the peculiarities of pig manure as a substrate for biogas production depending on the classes of animals and the place of origin of raw materials. The goal of the present study of biogas potential of swine manure of different classes of animals (pregnant sows, lactating sows, piglets, fattening pigs) in Belgorod region of Russia. The experiment was carried out in small-scale batch reactors with the volume of 0.3 L each. Specific biogas yield from pig manure of different classes of animals ranged from 76.73 ± 11.77 to 151.42 ± 20.18 mn 3/t оDM, methane content – from 29.79 to 66.88%. In general, pig manure showed low biogas productivity. The highest rates were achieved at manure of sows. Taking into account the developed industry of pig breeding, biogas technologies, however, are the most optimal option of liquid manure utilization for the Belgorod region of Russia and are promising for many regions of the world with intensive animal breeding. When designing biogas plants, the specifics of local substrates should be taken into account.

The effect of phytoextract containing ecdysteroids and flavonoids on the metabolic parameters of pigs and white mice

The purpose of the research is to study the effect of extractive substances from a complex of herbs (R. Carthamoides, S. Coronate, F. ulmaria )on individual indicators of the metabolism of laboratory mice, pregnant sows and piglets obtained from them. A phytoextract containing ecdysteroids and flavonoids was orally administered to white mice ( three experimental and one control group of 15 mice) in doses of 0.1; 0.2 and 0.3 ml during 14 days that provided an increase in the average daily weight gain by 20.8-48.5% (P <0.05) in comparison with the control. The introduction into the diet of pregnant sows (three experimental groups and one control group of 10 sows) of an additive containing a phytoextract once a day at doses 3, 5 and 10 grams per head within 30 days before farrowing did not cause deviations from the norm of the studied biochemical blood parameters (total protein, albumin, cholesterol, calcium, phosphorus, magnesium, urea, creatinine, ALT, AST). The blood parameters of sows in the experimental groups characterizing the metabolic status of the organism were within the reference limits: total protein 60.7±0.4-62.0±0.3 g/l; albumin 44.2±0.4-52.7±1.8 g/l; cholesterol 2.14±0.04-2.90±0.01 mmol/l; Ca 2.50±0.05-2.62±0.01 mmol/l; P 2.91±0.0-3.16±0.04 mmol/l; Mg 0.92±0.02-1.28±0.01 mmol/l; AST 27.6±2.4-29.3±0.5 units; ALT 23.7±1.1-26.9±1.3 units; urea 4.8±0.2-7.9±0.5 mmol/l; creatinine 101.2±3.5-110.0±2.1 mkmol/l. The number of newborn piglets obtained from sows in the experimental groups exceeded the indicator in the control (127 heads) by 6.2%, of which live by 10.6% (in the control, 113 heads), the number transferred for weaning by 11.2% (in control 107 heads), gross growth by 9.8% (control 887 kg). The rest of the studied parameters of piglets (average weight of a piglet during transfer, average daily growth, survivability) did not differ significantly from the control (P> 0.05). It has been established that the phytoextract had an anabolic effect on white mice, did not cause a negative effect on the studied biochemical parameters of metabolism in pregnant sows, and contributed to an increase in the number of live newborns in comparison with the control.

Efficiency of standardized ileal digestible lysine utilization for whole body protein deposition in pregnant gilts and sows during early-, mid-, and late-gestation.

The efficiency of SID Lys utilization (kSID Lys) in gilts and sows during early (days 48 to 52), mid (days 75 to 79), and late gestation (days 103 to 107) was investigated using 88 pregnant females (PIC 1050; 27 gilts, 27 parity 1 sows, 34 parity 2+ sows; 192.96 ± 22.84 kg at days 42 ±1 of gestation) and whole body nitrogen (N) retention balance studies. Females were assigned to 1 of 4 SID Lys levels ranging from 40% to 70% of the daily SID Lys requirements above maintenance for a parity 1 sow according to the NRC (2012) gestating sow model in each gestation period. Experimental diets were isocaloric (3,335 kcal ME/kg) and isoproteic (11.75 % CP) and dietary indispensable AA were set to meet or exceed 100% of AA:Lys ratios. The slope of the linear response to graded SID Lys intake was defined as kSID Lys. With the aim of increasing the accuracy of kSID Lys estimates, gilt data from the current study was combined with gilt data from a previous study conducted at the same facility using 4 SID Lys levels ranging from 60% to 90% of the daily SID Lys requirements above maintenance for gilts according to the NRC (2012) gestating sow model. Whole body Lys retention of the combined gilt data set was assessed with different broken-line and nonlinear models. The kSID Lys was 0.65, 0.38, and 0.52 for early-, mid-, and late-gestation, respectively, in gilts. A linear response to graded SID Lys intake was found in late gestation only in parity 1 and 2+ sows; kSID Lys was determined as 0.44 and 0.52 in late gestation for parity 1 and parity 2+ sows, respectively. There were no differences in kSID Lys in late gestation between parities. For the combined gilt data, the model of best performance (reduced error and greater goodness of fit) was the Hoerl model. Maximum kSID Lys (i.e., g SID Lys retention/g SID Lys intake) in gilts was 0.67, 0.54, and 0.53 in early, mid, and late gestation predicted at 7.2, 9.1, and 13.5 g of SID Lys intake/d, respectively, based on the Hoerl model. Maximum SID Lys retention in gilts was similarly predicted at 8.5, 10.5, and 20.9 g of SID Lys intake per day in early, mid, and late gestation and resultant kSID Lys of 0.61, 0.51, and 0.44, respectively. The findings of this study demonstrate that kSID Lys varies by stage of gestation and SID Lys intake level and that, at least in gilts, a dynamic kSID adjusted for daily intake more adequately reflects biological response and hence allows more precise feeding of pregnant females.

Seasonal effects on fertility in gilts and sows

The ancestral wild pig is a short day length seasonal breeder. The domestic pig appears to have retained some of this seasonality as evidenced by a reduction in fertility during the summer—autumn period. The most important aspect of this seasonality is a reduction in the number of mated sows that farrow. Many of these sows conceive and embryos develop normally for 20 - 25 days before pregnancy is terminated and the sow returns to oestrus (25 - 35 days after mating). In other species, transduction of photoperiodic information is achieved by release of melatonin during the dark period. In the pig, the pattern of melatonin secretion and the subsequent hypothalamo—pituitary—gonadal responses appear to be more complex. A relatively high light intensity is required for pigs to generate a distinct diurnal melatonin rhythm and they appear unable to respond appropriately to abrupt changes in photoperiod. Pigs on restricted feeding and maintained under long photoperiods (but not under short photoperiods) have higher concentrations of melatonin than do similarly maintained pigs fed ad libitum. Continuous release melatonin implants have a deleterious effect on farrowing rate, suggesting that the abnormally high melatonin concentrations observed in sows in summer—autumn play a role in the pathogenesis of seasonal infertility. Ad libitum feeding of sows during the first few weeks of pregnancy may prevent the increase in melatonin concentrations and so remove the seasonal influence on fertility. The pituitary response to different photoperiods is also somewhat confusing. Although there is some evidence of increased sensitivity to the negative feedback of ovarian steroids in the prepubertal gilts and weaned sows during summer—autumn, LH concentrations are increased in early pregnant sows. It is proposed that the failure of sows to maintain pregnancy in summer—autumn results from disruption of maternal recognition of pregnancy causing regression of the corpora lutea, loss of pregnancy and return of the sow to oestrus.

Garcinol promotes hepatic gluconeogenesis by inhibiting P300/CBP-associated factor in late-pregnant sows.

Disorder of hepatic glucose metabolism is the characteristic of late-pregnant sows. The purpose of our study was to look into the mechanism of garcinol on the improvement of hepatic gluconeogenic enzyme in late-pregnant sows. Thirty second- and third-parity sows (Duroc × Yorkshire × Landrace, n 10/diet) were fed a basal diet (control) or that diet supplemented with 100 mg/kg (Low Gar) or 500 mg/kg (High Gar) garcinol from day 90 of gestation to the end of farrowing. The livers were processed to measure enzymatic activity. Hepatocytes from pregnant sows were transfected with P300/CBP-associating factor (PCAF) small interfering RNA (siRNA) or treated with garcinol. Dietary garcinol had no effect on average daily feed intake, body weight (BW), backfat and BW gain of late-pregnant sows. Garcinol promoted plasma glucose levels in pregnant sows and newborn piglets. Garcinol up-regulated hepatic gluconeogenic enzyme expression and decreased PCAF activity. Garcinol had no effect on the expression of PPAR-γ co-activator 1α (PGC-1α) and Forkhead box O1 (FOXO1) but significantly increased their activity and decreased their acetylation in late-pregnant sows. Transfection of PCAF siRNA to hepatocytes of pregnant sows increased PGC-1α and FOXO1 activities. Furthermore, in hepatocytes of pregnant sows, garcinol treatment also up-regulated the activities of PGC-1α and FOXO1 and inhibited the acetylation of PGC-1α and FOXO1. Garcinol improves hepatic gluconeogenic enzyme expression in late-pregnant sows, and this may be due to the mechanism of down-regulating the acetylation of PGC-1α and FOXO1 induced by PCAF in isolated hepatocytes.

Assessment of the Impact of the Recombinant Porcine Reproductive and Respiratory Syndrome Virus Horsens Strain on the Reproductive Performance in Pregnant Sows.

This study assessed the impact of a PRRSV (porcine reproductive and respiratory syndrome virus) recombinant strain (Horsens strain) on the reproductive performance of naïve pregnant sows in the last third of gestation. Fifteen sows were included: four negative reproductive controls (NTX), five infected with a PRRSV-1 field strain (Olot/91, T01), and six infected with the recombinant PRRSV-1 strain (Horsens strain, T02). Piglets were monitored until weaning. Reproductive performance was the primary variable. In sows, viremia and nasal shedding (T01 and T02 groups), and, in piglets, viral load in blood and in lungs, as well as macroscopic lung lesions (T01 and T02 groups), were the secondary variables. The reproductive performance results were numerically different between the two challenged groups. Moreover, viral loads in blood were 1.83 × 106 ± 9.05 × 106 copies/mL at farrowing, 1.05 × 107 ± 2.21 × 107 copies/mL at weaning from piglets born from T01 animals and 1.64 × 103 ± 7.62 × 103 copies/mL at farrowing, 1.95 × 103 ± 1.17 × 104 copies/mL at weaning from piglets born from T02 sows. Overall, 68.8% of T01 piglets and 38.1% of T02 piglets presented mild lung lesions. In conclusion, the results suggest that Horsens strain is less virulent than the field strain Olot/91 under these experimental conditions.

Evaluation of Cross-Protection between G1a- and G2a-Genotype Porcine Epidemic Diarrhea Viruses in Suckling Piglets.

Simple SummaryPorcine epidemic diarrhea (PED), caused by PED virus (PEDV), is a devastating enteric disease in pigs worldwide. At least two genotypes (G1 and G2) and five subgenotypes (G1a, G1b, G2a, G2b, andG2c) of PEDV strains have been identified. To date, the reports on the antigenicity and immunogenicity of those viruses are limited and the results documented on cross-neutralization among different genotypes and/or subgenotypes of PEDV were inconsistent. This study aimed to observe the comparative pathogenicity and cross-protection between G1a and G2a PEDVs, and thus find a new insight into the antigenicity and immunogenicity of PEDVs. The results of the present study demonstrated that the G2a-based inactivated vaccine could provide sterilizing immunity against both highly virulent homologous and heterologous PEDV challenges. In contrast, the G1a-based inactivated vaccine could induce a sterilizing immune response against challenge of homologous strain CV777 and only provide partial protection for the challenge of a heterologous G2a PEDV CH/JX/01. The findings of this study might explain the underlying mechanism that severe PED and deaths still occurred among the neonatal piglets of which CV777-based PEDV vaccine were administered in China, and imply G2a-based PEDV vaccine used in this study might be a good vaccine candidate for PEDV which may provide solid protection against circulating highly virulent PEDVs.To date, two genotypes, i.e., genotype 1 (G1) and genotype 2 (G2), of porcine epidemic diarrhea virus (PEDV) have been identified in swine, while the cross protection between the G2a and G1a subgenotypes is undetermined. Hence, in the present study, we attempted to observe a comparative pathogenicity and cross protection of G1a (CV777) and G2a (CH/JX/01) PEDVs. Initially pregnant sows were vaccinated twice with the two kinds of inactivated G1a- and G2a-based PEDV vaccines, respectively and the delivered neonatal piglets were challenged with prototype isolates of G1a and G2a PEDVs, and then the pathogenicity and cross-protection in neonatal piglets were observed. The results showed that CH/JX/01, a highly virulent and dominant G2a PEDV strain currently circulating in China had more severe pathogenicity in vitro and in vivo, and induced more strong immune responses, including higher titers of sIgA in maternal milk than that induced by CV777 PEDV, a prototype of G1a PEDV strain. All piglets from the sows immunized with CH/JX/01 could not only survive when challenged with the homologous PEDV, but also be fully protected when challenged with heterogenous G1a PEDV. In contrast, the piglets from the sows immunized with CV777 could be protected when challenged with homologous PEDV and only partially protected when challenged with heterologous G2a strain of PEDV (CH/JX/01). The findings of this study provide new insights into the pathogenicity, antigenicity, and immunogenicity of currently circulating wild type G2a PEDV, which might be valuable for the development of novel PEDV vaccine candidates with improved efficacy.

Comparison between Single- and Group-housed Pregnant Sows for Direct and Indirect Physiological, Reproductive, Welfare Indicators and Gene Expression Profiling

ABSTRACT Single- and group-housed pregnant sows were assessed during 8 weeks (4th and 8th to 14th) with regard to physiological, reproductive, welfare indicators and gene expression profiling. Compared to single-housed sows, group-housed sows had decreased non-return to estrus at 56 days after artificial insemination (AI) (83% vs 92%) and farrowing rate (78% vs 88%), respectively. Furthermore, group-housed sows showed a higher degree (p < 0.01) of advantageous physiological indicators, such as albumin (odds ratio [OR] = 4.4), alkaline phosphatase (OR = 1.5), bactericidal (OR = 3.2) and complement (OR = 24.3), and disadvantageous for alanine amino transferase (OR = 0.5), bilirubin (OR = 0.4), lysozyme (OR = 0.3) and C-reactive protein compared to single-housed. Eighty-seven genes related to immune response were underexpressed (log fold change ≤ 1.5; p < 0.05) during the 8th to 14th weeks in the group compared to single-housed sows, which in turn showed an immunomodulatory reduction on the expression of 43 genes during the 11th to 14th compared to the 4th week. Overall, the results were interpreted as indicative of greater comfort state of the group compared to single-housed sows.

Effects of mineral methionine hydroxy analog chelate in sow diets on epigenetic modification and growth of progeny.

The study was conducted to determine the effects of mineral methionine hydroxy analog chelate (MMHAC) partially replacing inorganic trace minerals in sow diets on epigenetic and transcriptional changes in the muscle and jejunum of progeny. The MMHAC is zinc (Zn), manganese (Mn), and copper (Cu) chelated with methionine hydroxy analog (Zn-, Mn-, and Cu-methionine hydroxy analog chelate [MHAC]). On day 35 of gestation, 60 pregnant sows were allotted to two dietary treatments in a randomized completed block design using parity as a block: 1) ITM: inorganic trace minerals with zinc sulfate (ZnSO4), manganese oxide (MnO), and copper sulfate (CuSO4) and 2) CTM: 50% of ITM was replaced with MMHAC (MINTREX trace minerals, Novus International Inc., St Charles, MO). Gestation and lactation diets were formulated to meet or exceed NRC requirements. On days 1 and 18 of lactation, milk samples from 16 sows per treatment were collected to measure immunoglobulins (immunoglobulin G, immunoglobulin A, and immunoglobulin M) and micromineral concentrations. Two pigs per litter were selected to collect blood to measure the concentration of immunoglobulins in the serum, and then euthanized to collect jejunal mucosa, jejunum tissues, and longissimus muscle to measure global deoxyribonucleic acid methylation, histone acetylation, cytokines, and jejunal histomorphology at birth and day 18 of lactation. Data were analyzed using Proc MIXED of SAS. Supplementation of MMHAC tended to decrease (P = 0.059) body weight (BW) loss of sows during lactation and tended to increase (P = 0.098) piglet BW on day 18 of lactation. Supplementation of MMHAC increased (P < 0.05) global histone acetylation and tended to decrease myogenic regulatory factor 4 messenger ribonucleic acid (mRNA; P = 0.068) and delta 4-desaturase sphingolipid1 (DEGS1) mRNA (P = 0.086) in longissimus muscle of piglets at birth. Supplementation of MMHAC decreased (P < 0.05) nuclear factor kappa B mRNA in the jejunum and DEGS1 mRNA in longissimus muscle and tended to decrease mucin-2 (MUC2) mRNA (P = 0.057) and transforming growth factor-beta 1 (TGF-β1) mRNA (P = 0.057) in the jejunum of piglets on day 18 of lactation. There were, however, no changes in the amounts of tumor necrosis factor-alpha, interleukin-8, TGF-β, MUC2, and myogenic factor 6 in the tissues by MMHAC. In conclusion, maternal supplementation of MMHAC could contribute to histone acetylation and programming in the fetus, which potentially regulates intestinal health and skeletal muscle development of piglets at birth and weaning, possibly leading to enhanced growth of their piglets.

Recombinant Lactobacillus acidophilus expressing S1 and S2 domains of porcine epidemic diarrhea virus could improve the humoral and mucosal immune levels in mice and sows inoculated orally

Porcine epidemic diarrhea (PED) is a highly contagious intestinal infectious disease caused by porcine epidemic diarrhea virus (PEDV), which is characterized by a high mortality rate in piglets. Since 2012, a remarkable growth in PED outbreaks occurred in many pig farms in China, landing a heavy blow on the pig industry. In order to develop a new effective vaccine for the current PEDV, oral vaccines were generated by transferring eukaryotic expression recombinant plasmids carrying the S1 and S2 (antigenic sites of the S protein) epitopes of PEDV into a swine-origin Lactobacillus acidophilus (L. acidophilus). After oral immunization of the BALB/c mice, higher levels of anti-PEDV specific IgG and SIgA antibodies and cellular immune responses were detected in mice orally administered with the recombinant L. acidophilus-S1 compared to the L. acidophilus-S2. Furthermore, L. acidophilus-S1 was used to inoculate the pregnant sows orally and the results showed that the recombinant L. acidophilus-S1 could elicit a specific systemic and mucosal immune response. In summary, our study demonstrated that oral immunization with L. acidophilus-S1 could improve the humoral and mucosal immune levels in sows and would be a promising candidate vaccine against PEDV infection in piglets.

Grass clover intake and effects of reduced dietary protein for organic sows during summer

Energy spent on thermoregulation and locomotive activity may increase the energy requirements of outdoor relative to indoor housed sows, whilst their protein requirement most likely is comparable on a daily basis but lower per kg of feed. The purpose of this study was to quantify the energy and protein intake from compound feed and grazing and the energy and protein needed for maintenance, maternal retention, milk production, thermoregulation and locomotive activity in organic sows during summer, to understand how nutrition of organic sows could be improved. A total of 41 2nd parity sows (Landrace x Yorkshire; 239 kg at insemination) were reared outdoor under organic conditions for six months. Sows were fed one of two iso-energetic diets, either commercial available gestation and lactation diets (control strategy), or a 12% lower protein supply obtained by diluting the control diets with a low protein supplement. Sows had ad libitum access to a plentiful grass clover sward and were supplied similar amounts of metabolizable energy (ME) from compound feed equivalent to 10% above the energy recommended for indoor sows. Collections of plasma and urine were performed on d 60 and d 100 of gestation and plasma, urine and milk was collected on d 5, 20 and 40 of lactation. On all sample collection days, sows (and piglets; n=671) were weighed individually, sows were back fat scanned and heart rate and locomotive activity was registered with a global positioning system (GPS) tracker. Sow body composition was estimated using a deuterium dilution technique, which allowed retention or mobilisation of protein and fat to be calculated. Grass intake was estimated via plasma pipecolic acid. Daily grass clover intake was on average 420 g DM/d during gestation, 574 g DM/d at peak lactation and 472 g DM/d on d 40 of lactation, corresponding to 2.4, 3.2 and 2.6 kg of fresh grass. There was an increased grass clover intake in the low protein group, as they consumed 14% more grass (37 g DM/d extra) than the sows fed the normal protein compound feed (P=0.007). Estimated milk yield peaked at 16.3 kg/d on d20. This experiment showed no effects of dietary protein level on urinary pH, urea or creatinine and no effects on plasma glucose, urea, lactate, triglycerides, creatinine or NEFA concentrations. It was possible to reduce the protein content of organic compound feed in the summer time as grazing pregnant sows obtained 16-17% of their daily SID lysine requirement from the sward in mid and late gestation. In conclusion, the daily protein- and amino acid requirements were met by feed and grass consumption during pregnancy but not in early and at peak lactation due to insufficient feed intake. The total energy requirement of high yielding second parity outdoor sows during a normal Danish summer was found to be around 32 MJ ME/d during gestation and approximately 130 MJ ME/d at peak lactation.

Bacterial communities associated to the urethra of healthy gilts and pregnant sows undergoing different reproductive protocols.

Nowadays, it is known that the urogenital microbiota plays a key role in the urinary health of mammalians. Despite the urinary infections affect the health and the welfare of breeding sows, the urethral microbiota of healthy sows remains unknown. Therefore, this work evaluates the urethral bacterial communities of healthy gilts and sows to determine the presence of Enterobacteriaceae populations, and the structure of this microbiota in gilts (G) and pregnant (P) sows. Samples were collected by scraping the urethral mucosa of G (n = 9) and P sows, which included natural mating (NM, n = 9) and artificial inseminated (AI, n = 7) sows. Samples were analyzed by culture-dependent techniques and 16S-rRNA gene high-throughput-sequencing. All females were positive for Enterobacteriaceae culture, without significant differences (Kruskal-Wallis) between G and P groups (median values: 2.78 and 3.09 log CFU/mL, respectively; P = 0.497). Also, the rate of Enterobacteriaceae/total mesophilic microorganisms was individually calculated, without significant differences between G and P sows (median values: 0.61 and 0.66, respectively; P = 0.497). When analyzing the bacterial communities, it was found similar richness in G, NM, and AI; however, diversity was lower in P sows than G (Mann Whitney/Kruskal-Wallis test, P < 0.01). The dominating phyla that constituted a "core microbiome" included Firmicutes, Proteobacteria, Cyanobacteria, Actinobacteria, and Bacteroidetes, which were common for all the studied females. The relative abundance for phyla, families, and genera was estimated, and Firmicutes was significantly higher in NM than AI sows (P = 0.02, Mann-Whitney/Kruskal Wallis test for univariate statistical comparisons); Pseudomonadaceae and Enterobacteriaceae were higher in AI than in NM (Mann-Whitney/Kruskal-Wallis, P < 0.05). Lactobacillus and Pseudomonas were among the dominant genera; however, only Pseudomonas sp. was significantly higher in AI than NM (Mann-Whitney/Kruskal-Wallis, P = 0.006). The results represent the first evidence about the existence of a urethral microbiota that includes Enterobacteriaceae, as well as the patterns of this microbiota in G and P sows. The knowledge of this urethral microbiota might allow for future research to develop innovative protocols to restore and/or preserve the healthy ecology of the urinary microbiome to prevent diseases ensuring the welfare of breeding sows.

Biofilms of pathogenic bacteria in pig industry

In the industrial pig farm for 26 thousand heads, the analysis of the influence of a forage factor on bacteria carriers of a uterine pig population in connection with mass morbidity of dairy piglets on anaerobic enterotoxemia is carried out. Actinobacillus pleuropneumonia, Pasteurella multocida, Clostridium perfringens, Neisseria spp., Candida albicans, Aspergillus niger which are able to form biofilms, were isolated from five samples of “SK-1” compound feed for pregnant sows and from the blood of animals (n=20) fed with this compound feed. The structural basis of the most stable biofilms in vitro were the aerobic fungi Aspergillus niger and Candida albicans. Biofilm-forming variants of these bacteria showed multidrug resistance to 30 antimicrobial drugs (synthetic penicillins, cephalosporins, fluoroquinolones, aminoglycosides, tetracyclines, combination drugs). Isolates of associative microflora isolated from the blood of sows were pathogenic for 30% of laboratory mice. It was found that probiotic agent No1 (composition based on Bischofite with probiotics) showed the universal bactericidal activity against the bacteria Actinobacillus pleuropneumonia, Pasteurella multocida, Clostridium perfringens, Neisseria spp.